General:

Mexican plant begins production August, 1988. It is the only place Golfs
and GTIs are built (some leftover 1988 USA-built models are remade into
1989s).
Gas-engine rear drum brakes go to 200mm (from the 180mm of all previous rear
drums). Diesel engines retain 180mm drums. Also, a new handbrake design
with a vinyl boot (leather on Carat and GLI) replaces the older, plastic
cover design.
Switch to bigger wiper splines. No wiper arm wings as in previous year
GTI/GLIs.
Cruise control and MFA stalks get bigger tumb grips for sliders.
California emissions laws require
stricter engine management standards, and as a result, all 8v models
sold in California include Digifant 1, with enhanced engine diagnostic
features and EGR systems. 16v systems already have this functionality,
and as a result only get an EGR system and an easier way to access
existing diagnostic features (Check Engine Light).
Golf and GTI 16V made in Mexico. They get Central Electric
1 (same as Mexican-built Jetta GLs). Shares many components
with Jetta which were previously different, including dashboard,
electrical system, wiper system, carpet, seats, interior trim, many colors, and more.

Jetta/Jetta GL:

Changes from last year:
Most (but not all) Jetta GLs produced in Mexico. Some still built in Germany.
Also for 1989, the Base model Jetta gets new upholstery and door panel trim, and
a black-painted trunk filler panel, like the GL. The Jetta Diesel also returns
to the USA for 1989, initially as an unannounced production run of 200 cars to
test market response, then as a full-fledged option.
Power steering, Height adjustable driver's seat and illuminated vanity mirrors
standard on GL.

There was also a second version available (according to VW, this one only came
in Canada), with the same interior, but the
exterior paint was either Star Blue Metallic or Alpine White. It had, in
addition to the above:
power/heated
mirrors
rear spoiler
fender flares
sunroof
power steering (standard on US
models)
ski sack
4
spoke wheel
delayed dome light

Jetta Flair (Canada only):

The Jetta Flair includes
special interior trim that matches the gray velour and leatherette
bolsters on the previous year's GLI Recaro seats (gray and leatherette), but on a standard seat. It also is
available in a special color, Pewter Metallic (LA7Y).